Safety and Seizure Control in Patients with Mesial Temporal Lobe Epilepsy Treated with Regional Superselective Intra-arterial Injection of Autologous Bone Marrow Mononuclear Cells

Temporal lobe epilepsy (TLE) is a highly prevalent syndrome among people with epilepsy, and is usually refractory to drug treatment. Structural and physiological changes, such as hippocampal sclerosis, are often present in TLE patients. The objective of this study is to evaluate the feasibility and safety of intra-arterial infusion of autologous bone marrow mononuclear cells (BMMC) in adults with medically refractory mesial temporal lobe epilepsy (MTLE) and unilateral hippocampal sclerosis (MTLE-HS). We enrolled 20 patients that had been diagnosed with MTLE-HS and refractory to medical treatment. All patients underwent a neurological evaluation, magnetic resonance imaging (MRI) with hippocampal volumetry, video-EEG with ictal recording, and a neuropsychological test battery focusing on verbal and nonverbal memory domains. After bone marrow aspiration and subsequent cell preparation the BMMC were infused by selective posterior cerebral artery catheterization. Patients were followed for 6 months. Safety of the procedure, seizure frequency, neuropsychological evaluation, EEG variables, routine brain MRI, and hippocampal volumetry were considered measurements of outcome. Any serious intercurrent clinical event or adverse effects related to the procedure were reported. No additional lesions and no significant hippocampal volumetric changes were observed. EEG recordings showed a decrease in theta activity and spike density. At 6 months, 8 patients (40%) were seizure free. A significant increase in the memory scores over time was observed. The BMMC autologous transplant for the treatment of temporal lobe epilepsy is feasible and safe. The seizure control achieved in this novel study supports the therapeutic potential of stem cell transplants in MTLE-HS patients.